Amp and speaker matching

Learn from the best in the business.
Topics with high educational content can be started here, or will be moved here from other forums.

Moderator: Dave Miller

Amp and speaker matching

Postby djconroy » Tue Aug 15, 2006 1:37 pm

I bring this question to the pros so I can learn.

Let's say I've got 4 PV 215 cabinets @ 4 Ohms each, with a rated program power of 700W each.

Would it be OK to run, say a QSC PLX3402, rated at 1700W/channel @ 2Ohms, with 2 cabs off each channel?

If I understand the calculations, if I put 2 cabinets on one channel, I'll wind up with a 2 Ohm load, and need to feed double the wattage to support both cabinets, correct?

Of course, I'm sure people would recommend bi-amping the cabinets, but that would require ripping them open and changing the wiring and adding jacks, thus voiding the warranty, no?
Active Member
Active Member
Posts: 52
Joined: Tue Nov 22, 2005 5:26 pm
Location: Milford, CT

Postby dokai » Tue Aug 15, 2006 3:47 pm

I'm not familiar with the PV 215 cabs, but the math says you can do it. You'd have to feed 1400 watts into each side in order for all four of the speakers to see 700 watts each. I don't know if you have to open the speaker cabs to switch them to bi-amp mode, but I'm betting that opening the cabs would void the warranty unless done by a Peavey-approved service center.

FYI, I've never been very comfortable driving two ohm loads, no matter WHAT the amp manufacturer says, but I may be just being conservative.
"You are what you do when it counts."
User avatar
Gold Premium Member
Gold Premium Member
Posts: 1173
Joined: Thu Feb 03, 2005 2:27 pm
Location: Richmond, RI

Postby TheBartman47 » Tue Aug 15, 2006 10:24 pm

You can do it, but I would not recommend trying to run it at full power that way. Though an amp will drive a 2 ohm load, it is usually not in your best interest to do so, mainly because of drastically reduced dampening factor. Also, your amp being 1,700 Watts at 2 ohms means 850 watts potential per PV215 cab. This is a little over the program rating, so extreme caution should be used. Probably as long as you don't run it loud enough to make the peak indicator LEDs come on, then you'll be ok. If your planning to drive these speakers at a light "cruising speed" and not running full-tilt-boogie, then it's really no problem at all. Just be carefull when pushing the system hard.
Senior Gold Member
Senior Gold Member
Posts: 1380
Joined: Wed Oct 20, 2004 1:37 pm
Location: Denison, TX

Return to DJGold University: Education for Pro Mobile DJ's

Who is online

Users browsing this forum: No registered users and 2 guests